Implantable Medical Devices (IMDs) have been designed or proposed to treat various conditions. For example, some IMDs are designed to treat cardiac conditions and perform functions such as pacing, cardioversion and defibrillation. Some IMDs deliver neural stimulation. By way of example and not limitation, neural stimulation has been proposed as a therapy for respiratory problems such a sleep disordered breathing, blood pressure control such as to treat hypertension, cardiac rhythm management, myocardial infarction and ischemia, heart failure, epilepsy, depression, pain, migraines, eating disorders, obesity, inflammatory diseases, and movement disorders. NeuroCardiac Therapy (NCT), as used herein, refers to neural stimulation delivered for a cardiovascular therapy. NCT, by way of example and not limitation, includes the stimulation of an autonomic neural target to provide a therapy for a cardiac arrhythmia, ischemia, heart failure, angina, atherosclerosis, blood pressure, and the like. By way of example and not limitation, autonomic neural targets used to deliver NCT include the vagus nerve, cardiac branches of the vagal nerves, baroreceptors, chemoreceptors, cardiac fat pads, the spinal column or some nerve roots extending from the spinal column.
Some current and proposed neural stimulation therapies are delivered for periods on the order of minutes, days, weeks, months or years. If the neural stimulation therapy is associated with an undesired response, the chronic nature of the therapy may exacerbate the undesirability of the response, as it can have long-term consequences for the health or quality of life for the patient. NCT, as currently envisioned, has side effects that may be occasionally intolerable or inconvenient. For example, the therapy may change heart rate and blood pressure at undesirable times. Other examples of side effects involve the laryngeal vibration or cough attributed to vagal nerve stimulation.